The Salt King by Natasha Pulley

Avelyn Brocken is a Jesuit at the Vatican. Originally from the salt mining town of Hreodwater in East Anglia, his only ambition is never to go back. But when rumours of miracles being performed there are followed by a bizarre video showing that someone trying to leave then enclave has been turn to salt, the Vatican foreign ministry summons him.

The isolated Hreodwater salt mine has its own culture, its own language, and its own faith - the worship of the Salt King, the sleeping god of the mine. Any investigation into their miracles requires someone who understands all three. Avelyn must go.

Returning to Hreodwater, with its unique salt light, and ability to destroy anything electronic within minutes, is personally challenging for Avelyn, who escaped the cult - and the Salt King - as a child. But eruptions of salt are happening all over the world. People are being turned into salt statues without warning, and their frequency is increasing. If these are miracles, the church must do something. And it they are not - if the ancient, and frightening, Salt King is returning - then Avelyn may be the only one who has a chance of stopping it . . .

The Salt King is a gorgeous and creepy fusion of folk horror with biblical lore from the genre-disrupting author of The Watchmaker of Filigree Street and The Mars House.